You could use Nuclear energy to extract oil. If you really need oil that could make a lot of sense. For example if you need it for chemical processes or as fuel.

The EROI is only a limiting factor if you look at all your energy sources combined. For example, Saudia Arabia (or rather Canada with their oil sands) could invest in Solar and Nuclear to keep extracting and exporting oil even though the EROI of the oil wells themselves fall below unity.